Unfortunately CR doesn't support more than one link to css, I hope it will be supported in the future. In order to see indentation in this epub you might edit testpage.html. Now it looks like:
Code:
<link href="../Styles/stylesheet.css" rel="stylesheet" type="text/css" />
<link href="../Styles/page_styles.css" rel="stylesheet" type="text/css" />
It should work, if you will comment link to page_styles.css or just place link to stylesheet.css below page_styles.css. Sure it is not solution, just workaround for CR deficiency in css support.